## Daniel Bath

Daniel Bath obtained his phD under the supervision of Uli Walther and is now on a post doctoral position at the university of Leuwen. His research is in algebraic geometry singularity theory and commutative algebra, often related to D-modules. More specifically he worked on Bernstein Sato ideals of an analytic map, notably in the case of hyperplane arrangments, and made substantial progress in the question of determining the zeroes of these ideals which have a combinatorial significance. He looked also at the question of making free a tame arrangement, by an addition of hyperplanes. Recently he adressed the question of the logarithmic comparison theorem, in the twisted and untwisted cases, and solved in particular an old conjecture by Terao and Yusvinsky. He continued in this direction with a paper in collaboration with Morihiko Saito, where they look at the same problem for locally quasihomogeneous divisors. These subjects are closely related to centers of interest in the Larema, for those working in singularity theory, first with Michel Granger, but also with other colleagues like A. Assi, Etienne Mann, V. Roubtsov, and others.

Michel Granger wrote a number of papers with co-authors widely refered to as well as himself, in D Bath papers. Our common interests involve various aspects of logarithmic vector fields and differential forms, sufficient conditions of freeness, and local or global comparison theorem in the case of semiinvariants in prehomogeneous spaces, or in the case of the so-called linear free divisors. There is a strong incentive for us to compare results and methods. The same is true about Bernstein Sato polynomial and ideals, about which Granger had a narrow look at papers about their generators in the free or in the generic case.